Influence of the Cohesive Zone Model Shape Parameter on Asphalt Concrete Fracture Behavior

Author(s):  
Seong Hyeok Song ◽  
Glaucio H. Paulino ◽  
William G. Buttlar ◽  
Glaucio H. Paulino ◽  
Marek-Jerzy Pindera ◽  
...  
2016 ◽  
Vol 43 (3) ◽  
pp. 226-232 ◽  
Author(s):  
S. Pirmohammad ◽  
H. Khoramishad ◽  
M.R. Ayatollahi

In this paper, the effects of the main asphalt concrete characteristics including the binder type and the air void percentage on the cohesive zone model (CZM) parameters were studied. Experimental tests were conducted on semi-circular bend (SCB) specimens made of asphalt concrete and the fracture behavior was simulated using a proper CZM. The CZM parameters of various hot mix asphalt (HMA) mixtures were determined using the SCB experimental results. Five types of HMA mixtures were tested and modeled to consider the effects of binder type and air void percentage on the CZM parameters. The results showed that as the binder in HMA mixture softened, the cohesive energy strength increased, whereas enhancing the air void percentage led to reduction of the cohesive energy and strength values. Among the studied HMA mixtures, the highest values of CZM parameters were found for the HMA mixture containing a copolymer called styrene-butadiene-styrene.


2015 ◽  
Vol 744-746 ◽  
pp. 1320-1323
Author(s):  
Hua Zhang ◽  
Hai Wei Zhang ◽  
Feng Su

The cohesive zone model (CZM) is being increasingly used to simulate fracture and fragmentation processes in metallic, polymeric, and ceramic materials and their composites. The CZM regards fracture as a gradual phenomenon in which separation takes place across an extended crack tip. This paper introduces the concept of CZM, the constitutive relations of CZM, the influence of the shape of the interface law and up-to-date applications of CZM to bituminous mixtures and pavement structures. Furthermore, some current challenges and the future directions to the modeling of fracture in bituminous materials and pavements are briefly discussed.


2013 ◽  
Author(s):  
Pritam Chakraborty ◽  
S. Bulent Biner

Fracture properties of Reactor Pressure Vessel (RPV) steels show large variations with changes in temperature and irradiation levels. Brittle behavior is observed at lower temperatures and/or higher irradiation levels whereas ductile mode of failure is predominant at higher temperatures and/or lower irradiation levels. In addition to such temperature and radiation dependent fracture behavior, significant scatter in fracture toughness has also been observed. As a consequence of such variability in fracture behavior, accurate estimates of fracture properties of RPV steels are of utmost importance for safe and reliable operation of reactor pressure vessels. A cohesive zone based approach is being pursued in the present study where an attempt is made to obtain a unified law capturing both stable crack growth (ductile fracture) and unstable failure (cleavage fracture). The parameters of the constitutive model are dependent on both temperature and failure probability. The effect of irradiation has not been considered in the present study. The use of such a cohesive zone based approach would allow the modeling of explicit crack growth at both stable and unstable regimes of fracture. Also it would provide the possibility to incorporate more physical lower length scale models to predict DBT. Such a multi-scale approach would significantly improve the predictive capabilities of the model, which is still largely empirical.


Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1278 ◽  
Author(s):  
Pengfei Liu ◽  
Jian Chen ◽  
Guoyang Lu ◽  
Dawei Wang ◽  
Markus Oeser ◽  
...  

To give engineers involved in planning and designing of asphalt pavements a more accurate prediction of crack initiation and propagation, theory-based models need to be developed to connect the loading conditions and fracture mechanisms present in laboratory tests and under traffic loading. The aim of this study is to develop a technical basis for the simulation of fracture behavior of asphalt pavements. The cohesive zone model (CZM) approach was applied in the commercial FE software ABAQUS to analyze crack propagation in asphalt layers. The CZM developed from the asphalt mixtures in this study can be used to simulate the fracture behavior of pavements and further optimize both the structure and the materials. The investigations demonstrated that the remaining service life of asphalt pavements under cyclic load after the initial onset of macro-cracks can be predicted. The developed CZM can, therefore, usefully supplement conventional design methods by improving the accuracy of the predicted stress states and by increasing the quality, efficiency, and safety of mechanical design methods by using this more realistic modeling approach.


Author(s):  
Javed Iqbal

Abstract: This study describes the development of Continuum and Discrete Damage Models in commercial finite element code Abaqus/Standard. The Concrete Damage Plasticity Model has been simulated, analysed, and compared the result with the experimental data. For verification, the Cohesive Zone Model has been simulated and analysed. Furthermore, the Extended Finite Element Model and concrete damage model are discussed and compared. The continuum damage model tends to simulate the complex fracture behaviour like crack initiation and propagation along with the invariance of the result, while the cohesive zone model can simulate and propagate the crack as well as the good agreement of the result. Further work in the proposed numerical models can better simulate the fracture behaviour of asphalt concrete in near future. Keywords: Model, Concrete, Cohesive Zone, Finite element, Abaqus.


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